Medics tend to a victim of the Tucson carnage. Soon after, so-called pundits began blaming "violent rhetoric," without knowing the facts. Photo: AP

We will know.

This is how the mur derous slaughter in Tucson differs from the Virginia Tech and Columbine massacres. The killers in those cases were dead by the time they ended, and their suicides ensured we would never be able to get to the bottom of them — what combination of their own genes, upbringing and cultural influences led these monsters to such bottomless evil.

But Jared Loughner isn’t dead. His apprehension means we will eventually have a definitive explanation for this act — that it won’t be left to ideologically interested parties to stitch together a politically convenient explanation from a diary entry, a MySpace page, a YouTube video and the recollections of classmates who barely knew him.

That matters. Knowing what had been at work in the case of the Beltway snipers in 2002 made a difference in getting the DC area back to normal.

As in that case, we will know. Alas, that fact is insufficient or unsatisfying for the chattering classes. Our compulsive hunger always to know first, speak first and decide first has only been amplified by the fact that we can now all participate instantly in a virtual version of a national cocktail-party conversation on Twitter, Facebook and blogs.

We must say something, even when we know nothing. So, in the guise of sober moralism, we have been told by self-satisfied solons on the Web sites of the Atlantic and The New Yorker that the possible root of Loughner’s crime can be found, say, among those who’ve dared to use the word “socialist” to describe Barack Obama’s policies.

But since we really don’t know a thing about Loughner’s motivations, the chattering-class conversation quickly came to center in the hours after the event on the notion that he had emerged like an evil Golem from the clay of the “violent rhetoric” of the political discussions of the last few years.

This led to some moments of comic interest, as when Keith Olbermann, apparently having forgotten his 15-minute rants against George W. Bush for destroying democracy, demanded an end to incendiary rhetoric in politics.

The novelist Ayelet Waldman asked me on Twitter to inform her of the occasions on which I had denounced violent rhetoric only an hour after she had demanded of the House speaker, “Crying yet, you sc–bag?” and referred to the “evil political hackery of the RNC.” She is, she wrote, “a Jew with a sense of history,” though evidently that sense of history lasts approximately the time it takes to write a tweet.

Markos Moulitsas of the Daily Kos, the most important figure in the leftist blogosphere, made himself notorious in 2004 for greeting the murder of four private contractors by Iraqi insurgents in Fallujah with the words “screw them.” He greeted the news of Saturday’s massacre with the words “F—ing American Taliban,” echoing the title of his own recent book.

Unquestionably, American political rhetoric can be repugnant, and the Right can certainly be as guilty as the Left. But think of it this way. In 2010, 90.7 million votes were cast in this country; in 2008, 131 million. If the political rhetoric being used in the United States were so incendiary that it leads people to murder, wouldn’t there al ready have been more of it?

The great fear, of course, is that now there will be — that this crime has opened a new door into a kind of anarchic free-for-all. The greater possibility is that Saturday’s events will literally increase the distance between elected politicians and their constituents in a way that will be injurious to the good working order of the United States.

So Loughner’s alleged crime will have far-reaching consequences. It will change American politics for the worse.

Not because of thoughts and ideas some of us don’t like. But because of actions. Crimes. Evildoing. johnpodhoretz@gmail.com